Chapter 6 Target Mode
Page 6 - 16 |
| Target Mode Response Command |
The
Response command. The format is as follows:
Note
The RF3880 is acting as a target when executing a Target Mode Response command.
Note
A value of zero indicates a transfer of 4 billion bytes, and should not be used.
BITS
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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0 | 0 | ICC | TMO | 0 | DAT | DIR | 0 |
Table 50: Bit-meanings of Flags-1 Field
DIR Direction of Data Transfer - If a data transfer is required to complete a command, use this bit to inform the adapter of the direction the data is to be transferred. This bit is only significant if the DAT bit is set to one.
0 ⇒ Data transfer is from the initiator.
1 ⇒ Data transfer is to the initiator.
DAT Data Transfer - Use this bit to inform the adapter that the command it is to perform involves a data transfer. This bit is used by the adapter in conjunction with the DIR bit.
0 ⇒ Command requires no Data phase.
1 ⇒ A Data phase is required for this command.
TMO Target Mode Operation - This bit distinguishes Target Mode Response commands from Initiator Mode
0⇒ Initiator Mode
1⇒ Target Mode Response command.
ICC Inhibit Command Complete Interrupt - This bit is used to inhibit the interrupt that would normally notify you that the command has completed.
0 ⇒ Interrupt using the Interrupt level indicated in the Interrupt field of the Start Command List command, when the command has completed.
1 ⇒ Do not interrupt to indicate command completion.
LUN
When the initiator selected the RF3880, it specified a LUN in its Identify message. For reselection, this byte contains that same logical unit number (LUN).
VME Memory Address
When the SCSI operation requested by the initiator that selected the RF3880 involves a data transfer, this field contains the beginning Host memory address for the transfer. This field is ignored for SCSI transactions that require no transfer of data.
Transfer Count
The value placed in this field indicates the number of bytes to be transferred to or from Host memory. For some SCSI commands this is an indeterminate number. In that case, use the number of bytes allocated in Host memory for this Data area.
21020285 D | User’s Guide |
